This study is developed in the frame of the Project "Water harvesting and Agricultural techniques in Dry lands: an Integrated and Sustainable model in MAghreb Regions" (WADIS-MAR, www.wadismar.eu). Among its objectives, the Project aims at increasing groundwater availability through managed aquifer recharge in two watersheds of the Maghreb Region: Oued Biskra in Algeria and Oum Zessar in Tunisia. Prior to the design of the artificial aquifer recharge intervention, a detailed hydrogeochemical characterization of the study areas was carried out, including bulk chemistry and multi-isotopic analyses of water and solid samples. Results for the Algerian case study are presented. The Algerian area of interest is located in a flat region between the Saharan Atlas mountains and the Aures hills, is crossed by the Oued Biskra according to NS direction, and is characterized by the superposition of several folding events (Middle Eocene to Pleistocene) that strongly influence the geometry of the main aquifers. Coupled hydrochemical and isotopic results confirm previous hypotheses based mainly on structural geology, showing that the tertiary aquifers are connected one to the others, acting as a whole, and that the faults affecting the area could be acting as preferential pathways for the connection with the deeper cretaceous aquifers. Among other results, contamination by nitrate was identified near the city of Biskra, affecting the Quaternary and Miopliocene aquifers. The use of nitrate isotopes evidenced the origin of contamination to be probably related with wastewater. Analyses of Boron isotopes are being carried out to distinguish between wastewater and animal manure, while the lower delta15N values should be related to fertilizers. Isotopic composition of dissolved sulphate indicated that the origin of SO4 in most aquifer units is related to three sulphate origins: sewage, fertilizers, natural Triassic sulphates.
Isotopic tools applied to the hydrogeochemical characterization and the identification of contamination sources in the Oued Biskra watershed (Algeria)
ARRAS, CLAUDIO;BUTTAU, CRISTINA;CARLETTI, ALBERTO;DA PELO, STEFANIA;GHIGLIERI, GIORGIO
2016-01-01
Abstract
This study is developed in the frame of the Project "Water harvesting and Agricultural techniques in Dry lands: an Integrated and Sustainable model in MAghreb Regions" (WADIS-MAR, www.wadismar.eu). Among its objectives, the Project aims at increasing groundwater availability through managed aquifer recharge in two watersheds of the Maghreb Region: Oued Biskra in Algeria and Oum Zessar in Tunisia. Prior to the design of the artificial aquifer recharge intervention, a detailed hydrogeochemical characterization of the study areas was carried out, including bulk chemistry and multi-isotopic analyses of water and solid samples. Results for the Algerian case study are presented. The Algerian area of interest is located in a flat region between the Saharan Atlas mountains and the Aures hills, is crossed by the Oued Biskra according to NS direction, and is characterized by the superposition of several folding events (Middle Eocene to Pleistocene) that strongly influence the geometry of the main aquifers. Coupled hydrochemical and isotopic results confirm previous hypotheses based mainly on structural geology, showing that the tertiary aquifers are connected one to the others, acting as a whole, and that the faults affecting the area could be acting as preferential pathways for the connection with the deeper cretaceous aquifers. Among other results, contamination by nitrate was identified near the city of Biskra, affecting the Quaternary and Miopliocene aquifers. The use of nitrate isotopes evidenced the origin of contamination to be probably related with wastewater. Analyses of Boron isotopes are being carried out to distinguish between wastewater and animal manure, while the lower delta15N values should be related to fertilizers. Isotopic composition of dissolved sulphate indicated that the origin of SO4 in most aquifer units is related to three sulphate origins: sewage, fertilizers, natural Triassic sulphates.
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
